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NSG 2020 questions I got wrong - could someone please walk me through them? (1 Viewer)

nsw..wollongong

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for question 9, i think the only organic ones would be the propanoic acid and the HCN
 

SadCeliac

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isnt HCN cyanic acid??? which isnt technically organic?? just remembering now
 

SadCeliac

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okay what about the other two - the calc one i have no clue how to do and the radiation one i just need some clarification on what filtrate/residue is
 

bigman19191

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Question 8:

Ethanol and methanoic acid will reflux to produce ethyl methanoate (an ester). You should first write out an equation for this

Determine the number of moles of both ethanol and methanoic acid. This can be done by using n = m/MM
n(ethanol) = 3.50g / 46.068 g/mol = 0.07597 mol
n(methanoic acid) = 5.75g / 60.052g/mol = 0.09575 mol
Ethanol is the limiting reagent meaning it gets used up completely.
Therefore, the n(ethyl methanoate) = 0.07597 mol since they are in a 1:1 stoichiometry ratio

Now you can calculate the mass of the product extracted
m(ethyl methanoate) = 0.07597 mol x 74.078 g/mol = 5.63g

However, the mass was found to be 24% of the expected result
So 5.63g x 0.24 = 1.35g
 

SadCeliac

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Question 9:

Ethanol and methanoic acid will reflux to produce ethyl methanoate (an ester). You should first write out an equation for this

Determine the number of moles of both ethanol and methanoic acid. This can be done by using n = m/MM
n(ethanol) = 3.50g / 46.068 g/mol = 0.07597 mol
n(methanoic acid) = 5.75g / 60.052g/mol = 0.09575 mol
Ethanol is the limiting reagent meaning it gets used up completely.
Therefore, the n(ethyl methanoate) = 0.07597 mol since they are in a 1:1 stoichiometry ratio

Now you can calculate the mass of the product extracted
m(ethyl methanoate) = 0.07597 mol x 74.078 g/mol = 5.63g

However, the mass was found to be 24% of the expected result
So 5.63g x 0.24 = 1.35g
lifesaver tysm
 

SadCeliac

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I also have this question from later in the paper - no clue how to do it:
Screen Shot 2023-08-02 at 10.32.43 pm.png

Screen Shot 2023-08-02 at 10.33.29 pm.png
I estimated equivalence point at 8.2 ish but NO CLUE WHAT TO DO FOR C!!!

please help <3
 

bigman19191

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Question 9:

The two organic compounds are CH3CH2COOH (propanoic acid) and HOOCH (methanoic acid). They both contain a carboxyl functional group which is organic due to the presence of carbon. As such, the answer cannot the HCl nor H2SO4. HCN is not organic acid because there is no -COOH group.
 

SadCeliac

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Question 10:

The two organic compounds are CH3CH2COOH (propanoic acid) and HOOCH (methanoic acid). They both contain a carboxyl functional group which is organic due to the presence of carbon. As such, the answer cannot the HCl nor H2SO4. HCN is not organic acid because there is no -COOH group.
OH WAS IT ASKING FOR ORGANIC ACID???!?!?!
 

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